The Department of Occupational Health has established and coordinates a program to develop job-exposure matrices tailored to the general French population: the Matgéné program. A job-exposure matrix can be briefly described as a table showing the correspondence between job titles and exposure indices for one or more hazards. Exposures can then be automatically assigned to individuals based on their job titles. These matrices have numerous potential applications. In particular, they allow for estimating the prevalence of occupational exposures in the population and studying variations in this prevalence by sex, age, region, occupation, industry sector, and time period. They can also be used to assess occupational exposures of subjects in epidemiological studies, or as an aid in identifying exposures for prevention or medical and social care. The matrices produced are specific to a substance or group of substances. To ensure the widest possible applicability, each matrix includes all occupations and industries considered capable of generating exposure, along with the corresponding codes in several classification systems. Occupations and industries considered non-exposed are not included in the matrix. (R.A.)